package com.github.davidmoten.aws.lw.client.internal;
   
   import java.util.Optional;
   
   import com.github.davidmoten.aws.lw.client.Credentials;
   import com.github.davidmoten.aws.lw.client.internal.util.Preconditions;
   
   public final class CredentialsImpl implements Credentials {
   
      private final String accessKey;
      private final String secretKey;
      private final Optional<String> sessionToken;
  
      public CredentialsImpl(String accessKey, String secretKey, Optional<String> sessionToken) {
          Preconditions.checkNotNull(accessKey);
          Preconditions.checkNotNull(secretKey);
          Preconditions.checkNotNull(sessionToken);
          this.accessKey = accessKey;
          this.secretKey = secretKey;
          this.sessionToken = sessionToken;
      }
  
      @Override
      public String accessKey() {
          return accessKey;
      }
  
      @Override
      public String secretKey() {
          return secretKey;
      }
  
      @Override
      public Optional<String> sessionToken() {
          return sessionToken;
      }
  
  }